perf: reduce live worker capacity probes

[stainlu]

Reduces repair live-capacity GitHub Actions API probes by fetching recent workflow runs once and filtering active statuses locally. Also avoids an immediate duplicate capacity probe in the wait-for-capacity dispatch loop.\n\nValidation: build:repair, focused live-worker-capacity test, targeted oxlint, targeted oxfmt, git diff --check. Direct build in this checkout is blocked by non-writable generated dist files, so validation ran in /private/tmp/clawsweeper-perf-build.

[steipete]

This optimization is still directionally useful for rate-limit pressure, but the branch is dirty against current main. Please rebase before review/landing.

During the refresh, make sure it composes with the current workflow-active-run fixes on main: live worker/run counting should use supported GitHub data and local filtering, not unsupported gh run list --workflow / status-flag fallbacks. After rebase, please rerun pnpm run check.

[stainlu]

Rebased on current main and reran pnpm run check under Node 24. This now uses the workflow-runs API with local active-status/prefix filtering and avoids the duplicate dispatch capacity probe.